A 21-year-old Peace Corps volunteer was sexually assaulted on her way to buy lunch in her village overseas. The local police did nothing; the local Peace Corps staff told her the 2009 crime “probably wasn’t a big deal.”

A 23-year-old volunteer was strangled two years earlier before she broke free. Local police failed to gather evidence or take the crime seriously, leading the Peace Corps security officer to tell the victim that he would never ask a volunteer in the region to make a police statement because the response had been so unprofessional.

And a 27-year-old volunteer was warned by her host family that they were arranging for her to be kidnapped into marriage before the father entered her room one night in 2004 and raped her. After the Peace Corps security officer repeatedly told her “not to worry,” she did not report the rape but quit. “I had lost all faith in the Peace Corps to listen to me,” she wrote.

These are among the accounts of about 30 current and former volunteers who were sexually assaulted overseas, told in graphic sworn statements provided to congressional investigators. Most of the attacks occurred in the past four years — and some as recently as the past year — during a time when the agency says it has improved how it responds to violent crimes.

The lengthy affidavits reflect a difficult and troublingside of the Peace Corps, although it is hard to say how widespread violent crime is. The agency has acknowledged that underreporting is high and that its statistics are incomplete.

The statements were provided to the House Committee on Foreign Affairs as lawmakers held a hearing in the spring on the Peace Corps’ response to crimes against volunteers. New affidavits were submitted last week. They were forwarded by First Response Action, an advocacy group of former volunteers that is pressing the Peace Corps for more support for victims of sexual violence.

“The Peace Corps keeps telling us our stories are isolated incidents,” said Casey Frazee, First Response’s founder, who was sexually assaulted in South Africa in 2009. “We know it is different. There are hundreds, possibly thousands, of cases out there.”

The Peace Corps says it is already offering volunteers more support, with more rigorous training for security and medical staff and for volunteers in reducing their risk of assault. A victim advocate was hired this year.

In a statement, Director Aaron S. Williams apologized to volunteers who he said were “let down by the agency.”

“The health and safety of our volunteers is our top priority,” Williams said. “We are implementing numerous reforms to better protect [them] and provide effective and compassionate support to victims.” He said the Peace Corps is committed to working with Congress to strengthen its response to violent crime.

As Congress takes up several bills this fall that would force more changes, the statements offer a window into life on the ground for some.

The stories have common threads: unsafe housing, a slow or hostile response by local police, a minimal response by Peace Corps staff and discouragement from pursuing justice. Most victims are in their 20s, the age many volunteers sign up. Most are women.

Victims describe inconsistent responses, with some Peace Corps staff doing the best they can to help but others making little effort.

The Washington Post normally does not identify sexual assault victims; names and identifying countries in the affidavits have been redacted.

In 2008, the Peace Corps shifted responsibility for helping prosecute violent crimes from a team of federal criminal investigators with the inspector general’s office to the agency’s in-country security staff. A 2010 audit by the inspector general said staff lacked experience to handle criminal cases.

Another bill sponsored by House Foreign Affairs Committee Chairman Ileana Ros-Lehtinen (R-Fla.) would require the Peace Corps and State Department to come up with an agreement ensuring that U.S. Embassy officers would respond to Peace Corps cases.

“To fix the problem of inadequate response to crimes, the Peace Corps must consistently involve U.S. law enforcement personnel who are in the best position to support U.S. citizens who become crime victims in foreign countries,” Ros-Lehtinen said in a statement.

The agreement was urged by the inspector general 17 months ago. But an internal State Department memo to overseas officers in 2009 said the Peace Corps had primary responsibility for responding to crimes against volunteers.